1. Field of the Invention
The present invention relates to orthodontic retraction appliances, and more particularly to orthodontic headgear having "J" hooks for use in conjunction with so-called braces on teeth in which at least the relative positioning of the headgear and the "J" hooks is adjustable.
2. Prior Art
In orthodontics the use of braces on teeth to reposition and guide them for proper growth is well known. As an accessory to braces in certain situations, it is also desirable to apply an exterior, backward or upwad pulling pressure to the braces by means of spring biased "J" hooks in which the ends of the hooks are attached to the braces and the shanks or shafts of the hooks are attached by resilient biasing means to the headgear or a cap worn by the user. Examples of prior art patents are the U.S. Pat. Nos. to Dewoskin, 2,968,097 issued Jan. 17, 1961, and to Interlandi, 3,203,099 issued Aug. 31, 1965.
However, as a general proposition, these prior art systems were generally not adjustable or as readily or as easily adjustable as desired, and each user usually required a completely customized system, greatly adding to the inconvenience and expense of such systems.
One prior art attempt at making the "J"-hook attachment system adjustable has been the "SNAP-WAY" design of Northwest Orthodontics of Seattle, Wash., in which the "J"-hook assembly included two separate components, an adjustable length latch tab and a calibrated coil spring unit. The latch tab had a series of three, inclined-plane latches while the spring unit had an inverted "U," latch tab guide and an adjacent inverted "U" shape bridge into which the tab would be inserted, until the selected one of the inclined latches had passed through and was held by it. However, such a design has provided relatively little adjustability requiring several different models (for example small, medium, large and extra large for different size patients, is too limited in its application and is relatively more complex and expensive in its manufacture.
It is a basic object of the present invention to provide relatively simple, reliable and easily manufactured, adjustable orthodontic brace biasing systems which are relatively wide ranging in their adjustability and application, allowing for the same orthodontic headgear system to be used for different size patients and for applications requiring different amounts of pull and different directions of pull.